What’s the difference between a living collection of matter, such as a tortoise, and an inanimate lump of it, such as a rock? They are, after all, both just made up of non-living atoms. The truth is, we don’t really know yet. Life seems to just somehow emerge from non-living parts.

Featuring Jim Al-Khalili, professor of physics at the University of Surrey, and Sara Imari Walker, professor of physics at Arizona State University.

This episode is presented by Miriam Frankel and produced by Hannah Fisher. Executive producers are Jo Adetunji and Gemma Ware. Social media and platform production by Alice Mason, sound design by Eloise Stevens and music by Neeta Sarl. A transcript is available here. Sign up here for a free daily newsletter from The Conversation.

Further reading: 

Life: modern physics can’t explain it – but our new theory, which says time is fundamental, might